2010/10/1 Thom Brown <thom@linux.com>:
> But to find out what indexes you'll need, getting used to reading
> query plans will help as it will show you more than just where
> sequentials scans are taking place. It will also show you what the
> planner believes a query will cost compared to how much it actually
> costs, which can provide insight into tables which require vacuuming,
> indexes which might need clustering, or table stats which require
> modifying to match you data.
A couple related tools to help with explain plans are the query
analyzer in pgAdmin
(http://www.pgadmin.org/images/screenshots/pgadmin3_macosx.png), and
online at http://explain.depesz.com/
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